1. Technical Field
The invention relates generally to vacuum cleaners. More particularly, the invention relates to liquid bath vacuum cleaners. Specifically, the invention relates to portable vacuum cleaners designed for treating air by forcing the air through a fluid bath so as to remove the suspended particulates within the air flow and to a dual baffle system which reduces the amount of moisture migrating towards the exhaust.
2. Background Information
Vacuum cleaners of various designs are used in residential and commercial settings for cleaning purposes. These appliances develop suction to create air flow which picks up particulates from the surface being cleaned. These particulates are separated from the air within the vacuum cleaner for later disposal. One type of vacuum cleaner is a canister type which has a relatively stationary canister connected to a movable nozzle or wand by a flexible connecting hose. One design of canister type vacuum cleaner, known as a fluid bath type, directs incoming air and particulates into contact with a fluid bath thereby absorbing the particulate matter. Fluid bath vacuum cleaners have the significant advantage that their primary filtration mechanism employs a readily available commodity, water.
Numerous designs of fluid bath type vacuum cleaners are presently known. Although devices constructed in accordance with these patents perform satisfactorily, designers are constantly seeking to reduce the number and size of particulates that escape the vacuum cleaner and ultimately re-enter the environment. To reduce the particulate size and the number of particulates that escape the scrubbing process in the vacuum cleaner, the existing cleaners have either employed centrifugal force to separate the particulates from the fluid bath, or induced turbulence into the fluid bath. However, in those cleaners that attempt to induce turbulence, the intensity of the turbulence, as well as the length of time in which the turbulence is induced, are significant factors when considering the efficiency of the scrubbing process.
Inducing severe turbulence into the fluid bath causes the water to migrate upwards into a motor, following the direction of suction, which not only allows suspended particulate to re-enter the air, but also significantly reduces the efficiency of the motor itself. The United States Patent to Erickson, U.S. Pat. No. 4,640,697 provides as its main object, the separation of a cleaning air stream from a motor cooling air stream to improve the cooling efficiency of the motor and to prevent its contamination from the cleaning air thereby attempting to eliminate one of the problems discussed hereinabove. This is accomplished by mounting the motor assembly in a lower cavity so that the cleaning air is circulated through a plurality of scallops in a main housing before passing it to the surrounding atmosphere. Conversely, a cooling motor is mounted within a separate housing in a canister wherein the cooling air exits through gaps into an inner cavity and through a plurality of slits into the surrounding atmosphere. In this manner, the cooling air and the cleaning air travel separate paths, thereby allowing the motor's efficiency to remain high. However, such an arrangement does not counteract the increased migration of fluid toward the motor caused by increased turbulence within the fluid bath and as such, more suspended fluid will enter the surrounding environment.
U.S. Pat. No. 5,022,115, to Kasper, covers a vacuum cleaning system consisting of a vacuum canister assembly and a liquid pan mounted on the bottom of the canister for holding the fluid filter. The inlet includes a port on the side and lower surface of the vacuum canister assembly, and a pan has an upper surface which has an opening therein through which a portion of the inlet port extends. In essence, Kasper discloses a pan assembly that allows the pan to be detached and cleaned more easily. However, Kasper does not disclose means to prevent migration of water into the motor after an increased turbulence has been induced in the fluid medium.
U.S. Pat. No. 2,221,572 to Charles Bront et al. provides means to increase the turbulence within the fluid bath by discharging the cleaning air below the normal surface of the fluid bath. However, while this patent provides means to more absolutely scrub the cleaning air, means have not been provided to reduce the amount of moisture which will migrate into the atmosphere in which the unit is being employed due to the increased turbulence.
Other vacuum cleaners utilizing a fluid bath are shown in U.S. Pat. Nos. 2,945,553, 2,102,353, 2,886,127 and 2,221,572.